Radical grafting from carbon black graft polymerization of vinyl monomers initiated by azo groups introduced onto carbon black surface

Abstract

The radical graft polymerization of vinyl monomers from carbon black initiated by azo groups introduced onto the surface was investigated. The introduction of azo groups onto the carbon black surface was achieved by three methods: (1) the reaction of 2, 2′-azobis(2-cyano-n-propanol) with acyl chloride groups on the surface, which were introduced by the reaction of carboxyl groups on the surface with thionyl chloride, (2) the reaction of 4, 4′-azobis(4-cyanovaleric acid) with isocyanate groups on the surface, which were introduced by the treatment of carbon black with tolylene 2, 4-diisocyanate, and (3) the reaction of hydroxyl groups on the surface with 4, 4′-azobis(4-cyanovaleryl chloride). It was found that the polymerization of vinyl monomers such as methyl methacrylate and styrene was initiated by azo groups introduced onto the carbon black surface. During the polymerization, the corresponding polymer was effectively grafted onto the carbon black surface based on the propagation of the polymer from the radical produced on the surface by the decomposition of the azo groups. The percentage of grafting of poly(methyl methacrylate) and polystyrene using azo groups introduced by the method 2 increased to 40.0% and 28.5%, respectively. Furthermore, the effects of temperature and e-value of vinyl monomers on the graft polymerization were discussed. © 1990 The Society of Polymer Science, Japan.